Dr. Julie, a.k.a. Scientific Chick, brings you insights into what's happening in the world of life sciences. Straight from the scientific source, relevant information you should know about, in plain language.

Sunday, November 28, 2010

I consider myself a fairly healthy person and I rarely get sick. However, there is one activity that never fails to put me under the weather: flying. No matter how hard I try, no matter how much I wash my hands and try not to touch my face, any flight inevitably leads to some kind of illness. It usually ends up being a common cold, but I remember a nasty Christmas holiday spent in bed with a stomach flu. In any case, my recent flight home from San Diego was no exception, and here I am, still battling a stupid cold. So naturally, I looked for an article on how to prevent colds.

In a recent study, researchers followed over a thousand adults (18-85 years old) for 12 weeks during the fall and winter seasons. Over this time, the participants had to report two measures: any symptoms of upper respiratory tract infection (such as a cold), and how much they exercised.

While running in the cold winter air might sound like a counterproductive measure to prevent colds, the researchers found that participants who reported being physically active (aerobic exercise) five days a week or more experienced significantly less cold and flu symptoms (a 43% reduction in number of days with an illness). This relationship held true event when several factors were controlled for, such as dietary habits (eating lots of fruits and veggies) and stress levels.

Why might exercise prevent colds? While we don't have a clear cut answer to this question, animal studies suggest a few leads. When you exercise, you increase the circulation of cells that are important for immunity and that are involved in fighting off the bad guys. More specifically, exercise has been shown to boost macrophages (cells that eat up invaders) in your lungs. In addition, exercise can lower the levels of immunity-compromising stress hormones.

Is there anything exercise can't do? Now I need researchers to study how one can be motivated to exercise when they are sitting in a comfy chair by the fire with a mug of chai tea and a pile of work to do and it's below zero outside. Tell me something I don't know, right?

Thursday, November 18, 2010

I didn't have a chance to write a decent post this week because I was away in San Diego for the most glorious scientific event I know: the Annual Meeting of the Society for Neuroscience (SfN). I will resume regular programming shortly, but in the meantime, here are some highlights from the conference, in no particular order.

- The conference attracts over 34,000 neuroscientists and people wanting to sell stuff to neuroscientists. There were about 16,000 poster presentations. The event lasts 5 days and at any given time there can be a dozen talks going on. It's sometimes very hard to chose what to see. The Geek Meter registers very high.

- The opening session was a presentation by Glenn Close. She talked about her advocacy group for mental illness, Bring Change 2 Mind. She did a great job and I was moved. On a side note, she does NOT look 63.

- One of the highlights of SfN for many graduate students is the incredible amount of swag one can collect simply by feigning interest in a variety of products. The floor space for vendors is the size of a small city. This year I didn't have much time to go through it all, but I still managed to come home with two T-shirts, a mini laptop mouse, a notebook with a depiction of the Wnt pathway on the cover, and several pens.

- I would say that the two major themes this year were sensory (vision, olfaction, etc.) and Alzheimer's disease, even though there is definitely something there for everyone. There was also a big focus on optogenetics. My personal opinion is that optogenetics will revolutionize the field of medicine.

- Celebrity scientists are called scilebrities and can be spotted everywhere. The conference also organizes a number of socials for every field of neuroscience where you can narrow down your schmoozing to the scilebrities that work in your area of interest. You can usually judge how well a field is doing by the quality of the catering. It's a bit of a running gag.

- San Diego can pretty much be summarized in three words: fish tacos and tequila.

- As surprising as it may sound, neuroscientists know how to party. You're just going to have to trust me on this one.

I already can't wait for next year. See you soon for a post on how to keep colds at bay.

Sunday, November 7, 2010

I have fond memories of high school math classes. Numbers came easy for me, and I derived a lot of satisfaction from solving problems (and even more so when I solved them fast!). I was lucky to have excellent teachers, especially in grade 11 and in CEGEP, who turned math into something of a game, a code I needed to crack. However, I’m well aware that math class was not a party for everyone. About 15 to 20% of the population struggle with some form of difficulty in learning or understanding mathematics. Obviously, this can be an obstacle to success in school, and in employment. To address this issue, a team of researchers from the UK set out to test whether brain stimulation could improve someone’s math abilities.

The researchers used a technique called transcranial direct current stimulation (TDCS, similar to the method used in this post on morality). TDCS consists of applying a weak current to a brain region (in this case, the parietal lobe, a region important for learning and understanding of math) over a given time period (in this case, 20 minutes). The technique is non-invasive, meaning they don’t open up your scalp to get at your brain: electrodes are simply place on your head (volunteers are much easier to recruit when the electrodes are on the outside, not the inside). Depending on the type of current that the researchers apply, TDCS can increase or reduce the excitation of the brain cells in the targeted region.

To test the impact of this kind of brain stimulation on math capabilities, the researchers delivered the stimulation while the participants (15 healthy adults) were learning the relative values between nine arbitrary symbols (for example, square is bigger than triangle). The learning session lasted 90 to 120 minutes. The participants received either the brain stimulation during the first 20 minutes of the session (the experimental group), or only during the first 30 seconds of the session (the control group, as 30 seconds of the stimulation is not long enough to see any effects, but still gives you the “tingles” associated with the protocol). After this learning phase, the researchers assessed the participants’ newly created sense of numerical value for the symbols with two different math tasks using the symbols. This whole process was then repeated over six days.

The results show that brain stimulation leads to better and more consistent performance on both math tasks. Mathematical ineptitude is cured! To make the matters even more interesting, the researchers called the participants back six months later and re-tested them (no brain stimulation this time). And six months later, the brain stimulation group still performed better at the math tasks involving the fake digits.

While this may sound great, don’t start tazing your brain just yet. It’s worthwhile to note that on the last day of the initial six-day study, the researchers had the participants perform the same two math tasks, but with normal numbers. In this case, there were no difference between the experimental group and the control group. This means that the brain stimulation paradigm only worked for the specific task that was learned during the stimulation, and didn’t extend to math in general. Nonetheless, the researchers suggest that brain stimulation may be a tool for intervention for those who have “developmental and acquired disorders in numerical cognition” (read: for people who are bad at math).

Must we all be good at math? There’s a French saying that goes: "ça prend toute sorte de monde pour faire un monde" (roughly translates into: "it takes all sorts of people to make a world"). What’s your take on this? Do you think this is a great advance? Do you have any concerns? Let’s hear it!Reference: Modulating neuronal activity produces specific and long-lasting changes in numerical competence. (2010) Cohen Kadosh R et al. Current Biology 20:1-5.

About Me

Dr. Julie is an Assistant Professor of Neurology at the National Core for Neuroethics and the Djavad Mowafaghian Centre for Brain Health at the University of British Columbia. She holds a PhD in Neuroscience.